Brain waves are electrical signals of the brain measured on the scalp of a human, and the physical values of the brain waves reflect the state of the human with an electrical potential difference of several tens of micro-volts and a frequency of 30 Hz or less. There are four kinds of brain waves called the alpha wave, the beta wave, the theta wave and the delta wave. The beta wave is the brain wave at a frequency of 13 Hz or greater and is generated when the mental activity of a human is active. The alpha wave is the brain wave in a frequency range of 8-13 Hz and is generated when the brain of a human is in rest or in a stabilized state, which represents a typical brain wave of an adult. The theta wave is a brain wave in a frequency range of 4-7 Hz and is generated during a general dormant state. The delta wave is the typical brain wave in a frequency range of 0.5-3 Hz and is generated during a deep and sound sleep state. Up to the present, extensive research has been conducted on the study of brain waves. However, the research has not succeeded in sufficiently analyzing the information contained in brain waves. And as such, the interpretation of brain waves still remains unanalyzed.
There are a method of interpreting brain waves in the time domain and a method of interpreting brain waves in the frequency domain. However, the method of interpreting brain waves in the time domain requires much experience and skill, and it is difficult to discriminate the minute differences between brain waves by using such method. Presently, a frequency analysis method, which has been widely used in interpreting brain waves, needs to process the measured signals in order to easily analyze the state of the human body to be diagnosed in real-time.
A conventional brain wave measuring apparatus mainly uses cup-shaped electrodes, which are adhered to the scalp of the human head using a paste. Furthermore, a separately built-in card has to be included in a computer for analyzing the brain waves in order to receive and analyze a plurality of channels of the measured brain waves.
Korean Patent Laid-open Publication No. 99-46503 entitled “Real-time brain wave measuring apparatus using headband” on Jul. 5, 1999, which was registered as Korean Patent Registration No. 282733 on Nov. 30, 2000 entails this matter. However, the real-time brain wave measuring apparatus does not employ any pastes but is still able to measure brain waves from the scalp of the human head.
Moreover, brain waves are not only used for determining the health condition of the brain itself, but in addition, it is also important to distinguish brain waves from other signals (referred to as miscellaneous waves) that are generated from the other portions of the human body other than the brain, and to remove the miscellaneous waves from the brain waves so as to extract only the pure brain waves. Thus, the above-mentioned conventional art has failed to determine the health condition of an individual using the miscellaneous waves.
As such, in order to use the miscellaneous waves that are generated from respective portions of the human body, the miscellaneous waves need to be minimally removed from the brain waves and correspond to the brain waves due to the fact that the respective frequencies of the miscellaneous waves and of the brain waves are in a one-to-one correspondence relationship so as to determine the health condition of an individual. However, the conventional art has failed to determine the health condition of an individual using the one-to-one correspondence relationship between the frequencies of the miscellaneous waves and of the brain waves.